In general, a thermoelectric device comprises two opposite electrodes and a thermoelectric material (for example, a pair of a first thermoelectric material and a second thermoelectric material) interposed between the electrodes. The thermoelectric device utilizes the thermoelectric effect of the thermoelectric material such as a Thomson effect, a Peltier effect, or Seebeck effect to directly convert thermal energy into electric energy or electric energy into thermal energy. Furthermore, thermoelectric modules comprising thermoelectric devices arranged together in parallel have been put to practical use.
An example of such a thermoelectric device or module is described in “Diller, R. W., Bell, L. E., “Experimental Results Confirming Improved Efficiency of Thermoelectric Power Generation System with Alternate Thermodynamic Cycles,” Proceedings of the 22nd International Conference on Thermoelectrics Herault, France, August 2003. [searched on Jan. 19, 2010] Internet <URL:http://www.best.com/pdfs/Confirming-Results-TE-Power-Gen-Systems.pdf>. This document discloses a thermoelectric module comprising a high-temperature member, a thermoelectric material, a low-temperature member, a thermoelectric material, and a high-temperature member repeatedly and linearly arranged in this order.
However, in the thermoelectric module disclosed in the above-described Web page, the high-temperature member and the low-temperature member are each arranged between the thermoelectric materials. Thus, the thermoelectric module is used with the thermoelectric materials exposed to the atmosphere. Hence, the thermoelectric materials are, for example, oxidized or nitrided and thus degraded. The thermoelectric materials also degraded by water.